Numerous pharmaceutical or chemically active substances are preferably used in the form of solutions or mixtures with other ingredients or excipients. However, in practice, many of these active substances ae less stable in solution than in their solid state, or even incompatible with certain of the other ingredients or additives present in the solution in question. This is due, in particular, to the fact that when these mixtures are heated, for example, during a sterilization process, or kept for long periods, they give rise to chemical reactions which render their constituents completely inactive or at least substantially decrease their activity.
In the case of a number of clinical infusion solutions, it has proved advantageous to use combinations of glucose and amino acids of various types. The drawback, which is at present difficult to overcome, of these combinations lies in the incompatibility of the products when they are heated, and in particular, in the case of sterilization. The aldehyde group of glucose in effect reacts with the free amino moiety of the amino acids such as lysine leading, via Maillard reaction, to the formation of Schiff bases which are the cause, inter alia, of the dark colouring of these solutions. This type of rection does not only lead to modification of the physical aspect of these solutions, but also has a detrimental effect on biological compatibility, thus making the solutions completely unsuitable for infusion.
One of the solutions proposed as a remedy for these drawbacks consists in replacing, in sterilizable mixtures for infusion, glucose by sorbitol, as this latter product does not have any free aldehyde group. However, sorbitol has several drawbacks which limit its use from the legal point of view.
On the other hand, articles of diverse types have been suggested for dispensing volatiles, eminently odoriferous materials, into the surrounding atmosphere. Pertinent prior art in this regard has been discussed for instance in U.S. Pat. No. 4,161,283. In particular, this document discloses an article for the slow release of volatilizable substances, the article being formed from opposed outer and inner wall members joined along their peripheral portions to define a central reservoir portion for receiving and confining a volatilizable substance. The outer wall member comprises a non-pourous flexible polymeric sheet material which does not permit bulk flow, but allows molecular diffusion therethrough. The inner wall member comprises an impermeable barrier layer. Another barrier layer is releasably bonded to the outer wall and prevents escape of the volatilizable substance until its removal at the time of desired use. An embodiment of the prior disclosed article comprises a strippable adhesive layer bounded to the outer surface of the inner wall impermeable layer and removal of the strippable layer enables adhesive bonding of the article to environmental surfaces.
Compartmented package devices have also been suggested in the past.
Representative prior art include in this respect, for examples, U.S. Pat. No. 3,343,664 which discloses a compartmented package for dispensing a fluid conditioning medium and comprising a sealed substantially air-free storage container filled with a fluid conditioning medium and adapted to be opened and emptied without exposure of the conditioner into a sealed air-free dispensing container having flexible and collapsible wall portions through which the conditioner is diffusible. The opening of the storage container is effected at the desired time of use by gripping two triangular ear portions, which terminate the lower part of the dispensing device, and pulling them in opposite directions. Because of differing elasticity (the walls of the dispensing container should be made substantially more elastic than those of the storage container), the walls of the dispensing container will stretch in response to the applied force while the wall of the storage container will tear through its lower seal at a point wherein a cut has been made, thereby opening the storage container
U.S. Pat. No. 3,074,544 describes a multiple compartment flexible unitary package article for compartmentalized accomodation and selective admixture of at least two fluent materials which article comprises an envelope of flexible heat sealable sheet material, two opposing sidewalls of which are joined by heat sealing to form a transversely extending rupturable seam separating the interior of said envelope into individual compartments. In order to facilitate the rupture of the seam, this includes masking means in the form of a substantially uniformly open web interposed between said sidewalls and through the opening of which said sidewalls are heat sealed.
A device which has recently been developed for the perfuming of surrounding atmosphere comprises a pouch of specially adapted polymer material containing a perfuming solution (see International Patent Application WO 81/000051). These perform vapours diffuse slowly through the wall of polymer material and may thus perfume the environment for a long period. A problem arises, however, during the storage of these devices before activation.
In effect, as a result of the diffusion of the perfume vapours through the walls of polymer material of the packing, a considerable reduction in the initial amount of active substances may be observed.
To our knowledge, the above discussed prior art articles, though advantageous as they may seem, have not been commercialized so far. The reasons lie eminently in the difficulty encountered in their large scale manufacture especially in the realization of a reliable system enabling both safe storage of the active materials (or one of the active materials) and facility of activation by way of ready, "consumer-friendly" opening of the storage container.
It is an object of the present invention to provide a device which satisfies these apparently contradictory technical requirements.